The temporary creation of hairstyles for a longer time period up to a number of days normally requires the use of active setting substances. Hair treatment agents used for a temporary shaping of the hair therefore play an important role. Suitable agents for temporary shaping typically contain synthetic polymers and/or waxes as an active setting substance. Agents for supporting the temporary reshaping of keratin-containing fibers can be produced, for example, as a hairspray, hair wax, hair gel, or hair foam.
The most important property of an agent for the temporary shaping of hair, also called a styling agent hereinafter, is to give the treated fibers the greatest possible hold in the new modelled shape, i.e., a shape imposed on the hair. This is also referred to as a strong hairstyle hold or a high degree of hold of the styling agent. The hairstyle hold is determined substantially by the type and amount of the employed active setting substances, but the other components of the styling agent may also have an effect.
In addition to a high degree of hold, styling agents must satisfy a wide range of further requirements. These can be divided roughly into properties on the hair, properties of the particular formulation, e.g., properties of the sprayed aerosol, and properties related to the handling of the styling agent, particular importance being attached to the properties on the hair. Mention can be made in particular of humidity resistance, low tackiness (tack), and a balanced conditioning effect. Furthermore, a styling agent should be universally usable, if possible, for all hair types and be gentle to the hair and skin.
In order to satisfy the different requirements, many synthetic polymers for use in styling agents were already developed as active setting substances. These polymers can be divided into cationic, anionic, nonionic, and amphoteric setting polymers.
The European patents EP 1719499 B1, EP 1719500 B1, and EP 1726331 B1 describe acrylate resins with the INCI name of Acrylates/Hydroxy Ester Acrylates Copolymer and their use in styling agents. The international patent application WO 2012/054278 A2 also mentions Acrylates/Hydroxy Ester Acrylates Copolymers as hair-setting polymers and used by way of an example Acudyne® 1000 (The Dow Chemical Company) in hair foams.
Hairsprays based on copolymers of N-tert-butylacrylamide, acrylic acid, and ethyl acrylate are described, among others, in the German patent application DE 10 2004 040 172 A1.
Not every polymer or not every polymer mixture is basically suitable for the production of hair styling agents. This applies in particular to hairsprays in which, for example, the viscosity and thereby also the spraying behavior are influenced by the polymer or the amount of the polymer employed.
Furthermore, not every polymer and every polymer mixture is suitable for producing highly concentrated hair styling agents. With an increasing polymer concentration, apart from the previously described problems with the viscosity and dispensability of the agents, furthermore, there are difficulties in regard to solubility and storage stability in particular of hairsprays.
A hairspray with a high polymer content (compact hairspray) is described, for example, in the international patent application WO 2005/012588 A2.
Even if suitable polymers and polymer combinations have been developed for some time for use in styling concentrates in the field of temporary hair shaping, the results achieved so far continue to leave room for improvement, particularly in regard to storage stability, applicability, and the degree of hold of these agents. Currently available styling agents in particular can still be improved with respect to the fact that a good combination of the degree of hold and long-term hold (high humidity curl retention) is not always sufficiently assured.